GB1397541A - Monitoring apparatus for pipeline travellers - Google Patents

Abstract

1397541 Monitoring progress of pigs in pipelines ERNEST-LLOYD Ltd 17 May 1972 [17 Feb 1971] 4832/71 Heading G1N [Also in Division G4] The progress of a magnetic pig travelling through a pipeline is monitored by a series of detecting stations spaced along the pipeline, each of which sends a binary coded decimal serial pulse signal characteristic of the station to a common information receiving centre as a magnetometer at the station senses the pig. Each station has three thumbwheel switches X, Y, Z for setting its code, which upon detection of a pig is automatically transferred to a 12 position shift register 123 and read-out by 12 pulses from a clock 124 which is automatically stopped and reset to zero after the 12th pulse. The signals may be transmitted through the pipeline itself, if conductive, and the position of the pig indicated numerically and on a mimic diagram. The pig may be for scraping the pipe or for separating batches of fluid in the pipe.